1. Field of the Invention
The present invention concerns a fluid-operable rotary drive clutch.
2. Description of the Prior Art
A rotary drive clutch of this kind is used in machine construction to transmit the rotary movement of an input shaft to an output shaft as needed, the rotary drive clutch naturally being engaged or open, or being slippingly operated in the transitional range.
When the clutch is engaged, in order to transmit the required torque the drive plates concerned must be pressed together under high pressure via a piston/cylinder unit and an associated annular piston.
This function is performed by piston/cylinder units, from which operating fluid is delivered to the front face of the annular piston via a co-rotating pressure chamber. A basic problem with rotary drive clutches of this kind is the presence of sealing surfaces that rotate relative to one other, and that do so at the rotation speed of the input assembly at least when the clutch is engaged.
Hence, the only way to supply the pressure chamber in order to exert pressure on the drive plates is via a rotary leadthrough connected to a conduit system, one subconduit of which rotates at the shaft speed of the clutch and the other subconduit does not, and in which both subconduits are pressure-sealed against the pressure applied by the piston/cylinder unit.
A pressure-tight rotary leadthrough must therefore be provided between the output of the piston/cylinder unit and the conduit system communicating with the additional pressure chamber.
Particularly in the case of large machine installations, for example hydraulic presses used in the automotive industry, high pressures of up to about 100 bars must be sealed off via a leadthrough of this kind to prevent contamination of the environment.
Such a system is very onerous to design and build, however.